Spark-plug for internal-comrustion engines



C. L. FITZ.

SPARK PLUG FOR INTERNAL COMBUSTION ENGINES.

APPLICATION HLED SEPT. 4, 1917.

Patented Oct. 19, 1920.

INVENTOR. c4975. 1.. F/TZ BY .W'I TNESSES: WW

A ORNEYS.

UNITED STATES PATENT, OFFICE.

CHARLES LEO rrrz, or cmcaeo, ILLINOIS, ASSIGNOR ro- VISIBLE A CORPORATION or ILLINOIS.

SPARK PLUG 00.,

SPARK-PLUG FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Oct. 19, 1920.

Application filed September 4, 1917. Serial no. 189,522.

T 0 all whom it may concern Be it known that I, CHARLES L. Frrz, a subject of the Emperor of Austria-Hungary, residing at Chicago, county of Cook, and State of Illinois, have invented certain new and useful Im rovements in Spark- Plugs for Internalombustion Engines, of which the following is a specification.

This invention relates to improvements in spark plugs for internal combustion engines.

It is an object of the invention to combine with a plurality of electrodes or electrode portions of spark plugs means adapted to indicate the passage of current through the electrodes without making it necessary to remove the plug from its seat and to test it after removal in special apparatus.

Another object of the invention is to provide in combination with a spark plug a plurality of electrodes inserted into the core or body of the plug in such manner that the force of explosion occurring in each operative cycle of the engine will have a tendency to force the electrodes more firmly into the core.

Another obj ect of the invention is to place several electrodes of the same polarity into opposition to a single electrode of opposite polarity, providing thereby means for preventing the interruption of the spark if one of these electrodes should be covered by carbon, while in ordinary spark plugs the settlement of carbon on one electrode decreases the gap and leads to disturbance in the proper functioning of the plug and cannot be seen without testing.

With these and other objects in View, an embodiment of the invention is illustrated inthe accompanying drawing, and described in the following specification and claims:

Figure 1 is a longitudinal section through the spark plug, taken on line 12 of Fig. 2, showing two electrodes of different polarity in elevation;

Fig. 2 is a top plan view of the spark plug illustrated in Fig. l; N,

Fig. 3 {is a longitudinal section on line 2-3 of Fig. 2, the electr des being shown in elevation;

Fig. 4 is aside elevation of the spark of a ring or bushing 5 made of insulating and transparent material, like glass; this bu shlng 5 is surrounded by a metallic sleeve 6, which serves for protecting the bushing against breakage or the like. The top of the bushing 5 is covered by a cap 7 having a downwardly projecting flange 8, which surrounds the upper margin'of the bushing; an upwardly projecting flange 9 of the cap 7 surrounds a disk 10, which serves for introducing portions of the electrodes.

Both of the electrodes are well insulated against the material of the body 1. As in other spark plugs, one of the electrodes preferably is grounded and the other one is connected with a conductor supplying the electric current. The ungrounded electrode 12 is shown in Fig. 1 as a Wire with an enlarged tapering end, the taper projecting through the body portion 1 of the plug and the upper cylindrical portion of the electrode projecting through the bushing 5, through the cap 7 and through the disk 10 inserted in the cap. In order to insulate this non-grounded electrode against the cap 7 a bushing 13 of insulating material is introduced into the cap 7 and disk 10, the head portion of the whereby the conductor (not shown) may be detachably but firmly secured to this electrode.

In the present invention two grounded electrodes are provided, the lower portions 16 of which are constructed similar to the lower portion of the non-grounded electrode 12 described above. They consist of a tapering piece of metal insulated against but firmly inserted into-the body of the plug in such manner that a withdrawal of this electrode can be effected only in downward direction (as seen in Figs. 1 and 3).

The explosions occurring in the combustion chamber (below the plug) therefore will have the tendency to force the electrodes non-grounded electrode 12- and both of thesegrounded electrode portions 16, and the 0 eration of the plug will be interrupted. t

the same time, however, the current will pass through the plug without producing a ark at both the desired points in the combus ion chamber while a stronger spark will be produced at the under scribed below.

The lower or enlarged end of eachelectrode is provided with a bent wire or tip 17, as clearly shown in Figs. 1 and 3, the ends of these tips being sufliciently close .to each other to permit the passage of a spark and to cause thereby the ignition of the combustible ases in the cylinder. I

. The protecting sleeve 6 surrounding the transpartnt bushing 5 is provided with an aperture, so as to form a window 18 through which the electrodes may be observed. The grounded electrodes, as may be seen from Figs. 1, 3, and 4:, are not formed-as onepiece electrodes, but are each formed of two members 16 and 20, which are separated from each other a distance sufficiently large to permit the current to pass from one of these pieces to the other piece in the form of w a s ark brid in the ap. The upper one of these mem ier for ach of the grounded electrodes consists of a pointed screw 1n threaded engagement with a suitable opening in the cap 7 of the plug, the polnted or lower end being in close or direct opposition with a similarly pointed upper end 21'of the ta ering lower portion 16 of the electrode.

it is obvious, therefore, that the passage of current through the spark plug ma' be observed through the window 18. hen the operation of the plug is disturbed formation of carbon, a stronger spark wil pass from the upper portions 20 of the grounded electrodes to the lower portions 16 of the same. It is therefore not necessary to remove the plug from the cylinder and to place it in a special apparatus in order to test the same. It i s-also obvious that in a multiple cylinder engine the proper timing of the explosion may readily be noticed by observing the appearance and disappearance, and the intensity of the luminous spark in each of the spark plugs (pertaining to the various cylinders) through the observation windows v18 of the plugs.

Fig. 5 illustrates the circuit diagram wherein the double sparks are indicated at 23 and 24 respectively. The non-grounded conductor 25 leads to the electrode 12, from rounded electrodes being ormed portion of the plug as de- -whicha double spark23'jumpsto the sled 'trodes 16, the ot connected in multi 1e.-

er portlons of which are The test spark gap 24 1nay be observe through the window 18.

I claim:

1. In a spark plug, the combination of a body, a non-grounded electrode inserted in said body, an' electrode portion inserted in said body, a groundedelectrode portion in opposition to and alinement with said firstf namedelectrode portion, another electrode portion inserted in said body, a second grounded electrode portion in opposition to and alinement with said last named other electrode portion, a bushing, a cap mounted bod a non-groundedelectrode inserted in.

sai body, acap secured to said body and spaced therefrom, two grounded electrode vportions secured in said cap and extending from said cap p'arallelto each other to other grounded electrode portions in opposition" to said first named electrode portions, the

interspaces between grounded electrodeyportions secured to the cap and grounded electrode portions'secured to the body being at c equal distance fromthe cap, and abushing provided with a window through which both of the interspaces between the grounded electrode portions are visible.

3. A s ark-plu grounde electrode embodied in the body, an electrode-portion also embodied in the body, a grounded electrode-portion associated with and in opposition to the firstnamed electrode-portion, another electrode portion embodied in the body, a second.

grounded electrode-portion associated with and in opposition to the last-named other electrode-portion, 'a cap-element associated with the upper ends of the electrodes and to which the grounded electrode-portions are connected, and means juxtaposed to the' including a body, a nonwith and in opposition to the plurality of electrode-portions, the interspaces between the grounded. electrode-portions which extend into the cap and those embodied in the body being equi-distant from the cap, and a window-element associated with the body and cap and through which the interspaces are visible. r K

CHAS. LEO FITZ.

Ill 

